cheetah chrome

How many bolts hold the reference sensor(s) bracket to the bellhousing? Is it just the pivot bolt and the locking bolt? Can they be gotten at from the top?

Sam Lin

2, yes, yes (not easily)

Sam

pearldrum944

The Bracket is only held on by the 2 bolts. If the engine is in the car it can be pretty difficult to do but can be done. I spent about 2 hours replacing my sensors and the bracket because of the tight space. Good luck.

cheetah chrome

2 hours....I got ya beat by a mile...1st sensor took ~2 hours to get out...2nd sensor I put at least 5 hours into it only to have the head break off w/ the body still in the bracket/flywheel. Funny thing was I could spin the sensor (albeit took some pressure) but no go up and down. I heated up the bellhousing/froze the sensor/made up a gear puller type contraption out of a vice grip, all thread, and a aluminum bracket in attempt to walk the sensor out w/ a bolt (gave up on that idea because I couldn't get at it perfectly straight)/brute force/lots of penetrating oil. Luckily I have everything out of the way now so removing the bracket hopefully will go smooth(er). I'll work on that tomorrow need to make up an .8mm shim for my extra (suspected bad) sensor. Thanks for the help.

Will my car make it to Rennstock?...(shake up the magic eight ball)...outlook unknown

garthfan

I just did mine on my "S" not long ago. I pulled all the wires and hoses away from the bracket and tied them off out of the way. Then I ground down the allen wrench until the "working" end was only about 1/4" long. That made removing the bracket a snap. Of course, it takes a long time removing the bolts 1/8 turn at a time. lol. Other than that, it was pretty simple. I was replacing the sensors, anyway, so once the bracket and sensors were in my hand, I just punched them out from the bottom-up.

pearldrum944

Both of my old sensors broke in half (the top piece).

Ski

The problem can sometimes be the roll pin that fits into the block that goes with the "right bolt" hole looking down on it. When we converted the track car, we had one that the aluminum parted, leaving the skin in the hole and we pulled out all the copper windings in the sensor. That was fun to remove from the housing without destroying it.

dualblade

i forget if there's enough space in there but can standard hex head bolts be used instead of allen? it's just kind of a funny angle, and allen sockets not going in exactly straight will strip the bolt so easily..

cheetah chrome

what size is the allen key...I'll grind one down this evening. I also have everything tied back so I'm hoping it will go better than the fiasco leading up to it.

on another note my p-car project has been on the backburner for almost a year now, this is the first time in a while since I've had a chance to put some hours in tinkering. Even though things are not going as planned its a good reminder how much fun (and aggrevation at moments) it can be. Almost forgot what cut up hands and grease under the finger nails felt like hehe.

Thanks again (all) for the help!

David Floyd

Allen head socket, swivel joint, long or multiable extenstions, once you hit the hole, you can go to town from the top

cheetah chrome

FIXED = OK frustration had gotten the best of me and I used Scott's "not so caveman" method as descibed in this thread ...and as usual the guy is dead on. With both the pivot and the lock bolt out I couldn't remove the bracket because the speed sensor was still in. The bracket would slide out on the collar for the lock bolt enough to put a chisel in the gap. Slide a pipe onto the chisel for a longer lever and with very little force I was able bend the exposed end of the sensor enough I could pull the bracket and sensor out. The bracket is a very light cast and will bend, brake, mar easily...so if your frustrated go easy on it (I cracked the eyelit for the pivot bolt). * remember to stuff rags/papertowels into the empty reference sensor hole and the flywheel inspection hole so nothing goes in there!

Ref sensor bracket for my 87 951 (pretty sure it's the same for most 2.5ltr 944 series cars but check your bracket to be sure...number is cast in the bottom of the bracket) p/n: 944.101.321.03

User 41221

Sorry to be right about that one! Its nice to be able to fix it by just removing the darn thing, but its not always that easy. I've had to break three of those brackets off over the years, so I am pretty used to it, but it never quite feels like you are doing it the way Ferry would have wanted it done. lol Its a LOT quicker tho.

Regards,

Scuba Steve

How far off can the gap for the speed/reference sensors be? Mine looks around 2mm right now but I've never been able to get a tool into the allen head bolts to even adjust the bracket.

At the DME harness my digital multimeter reads in the mV, but I don't have a scope. I'm still trying to figure out if the sensor clearance is really that critical (.8mm), or if the problem is with the DME.

cheetah chrome

Spacing spec is .8mm +/-.3mm. If you want I can mail you a ref. sensor w/ an .8mm washer attached but I'll need it back ASAP to set mine. Looks like all of parts won't be in until after the holidays so it's doing me no good sitting here...at least until Santa (well the UPS guy) brings my next box o' goodies.

I haven't looked at the waveform w/ a scope either but I'd image being .9mm above the max spec would send a low amplitude signal to the DME...which I think requires at least 2V p-p (functioning correctly should be 2.5V p-p).

Scuba Steve

Actually my car already ate one .8mm washer today but things seem to be ok. I found a couple of broken or really bad traces on the lower DME circuit board affeting pins 9 and 11. They're fixed now but nothing changed.

The more I mess around with the sensor bracket, the more I think there's no way that thing could've moved accidentally since as hard as I try I can't make it budge. And the more I look at the DME I wonder how something that sits so still all the time could be bad. A scope is the missing piece of the puzzle here but I have no idea where to scare up one of those. At least I know the wiring between the sensors, and the sensors themselves are good.